1. Field of the Invention
The present invention relates generally to an item-supporting structure that can be used to support shelving or other elements for carrying or supporting any desired item. More particularly, the present invention relates to a support assembly for use in, for example, a knock-down shelving system, to adjustably support shelves.
The support assembly of the present invention can be ideally incorporated into a knock-down shelving system that includes a plurality of support posts for supporting one or more shelves at corner support assemblies thereof. The shelving system will include a snap-on wedge member with detent means for adjustably locating the wedge member at predetermined heights on the support post. In accordance with the present invention, each corner support assembly features a collar, which is structurally associated with the shelf, and a locking mechanism, or flipper, rotatably supported by the collar and actuable between a locking position and an unlocking position. In the unlocking position, the corner support assemblies allow the shelf to translate relative to the support posts. When the flippers are locked, the collars are secured to each respective wedge member and post by a wedging action. Operation of the flipper thus permits easy height adjustment of the shelf without the need for tools, and also without compromising the load bearing capacity of the shelving system.
2. Description of the Prior Art
Shelving systems having adjustable height shelves and so-called "knock-down" type shelving systems are known, and each has utility in many applications. For example, a knockdown shelving system with adjustable height shelves may be used in food service, industrial, commercial, hospital, and similar fields for storage of any desired items.
One type of known adjustable, knockdown shelving system is disclosed in U.S. Pat. No. 3,424,111 (Maslow) and U.S. Pat. No. 3,523,508 (Maslow), which are assigned to the assignee of the subject invention. The adjustable shelving system disclosed in these patents has achieved great commercial success under assignee's trademark SUPER ERECTA SHELF. This shelving system uses a plurality of cylindrical support posts provided with a series of equally spaced, annular grooves on its outer surface. A basic shelving system might include four support posts to support one or more formed-wire shelves, with each shelf having a frusto-conically-shaped collar at each corner for receiving a support post. A two-piece interlocking sleeve fits around the support post. The sleeve features a rib on its interior surface for engaging one of the grooves on the support post and has a frusto-conically-shaped outer surface, which is widest at the bottom, designed to complement the shape of the shelf collars. The support posts fitted with sleeves are received in the collars of each shelf to assemble the shelving system. When assembled, the weight of the shelf creates a radially-inwardly directed force between the collars and sleeves. This force brings the sleeves into a locking relation with the posts and creates a wedging force between the collars and sleeves.
While the SUPER ERECTA SHELF shelving system has proven very successful in providing an easy to assemble shelving system with a substantial load-bearing capacity, adjusting the shelves can sometimes require the use of a hammer or other tool to disengage the shelf collars from the sleeves. The weight of the shelf and any items supported thereon, especially over time, can build up the wedging force between the shelf collars and the sleeves to the point where a significant amount of force is needed to raise the shelf off of the sleeves.
A shelving system with easy to adjust shelves is provided in U.S. Pat. No. 5,415,302. This shelving system uses hanger brackets to permit easy installation and adjustment of the shelves without requiring the disassembly of the entire shelving system or the use of tools. This shelving system, known under the trademark QWIKSLOT SHELF, is also assigned to the assignee of the subject invention. The QWIKSLOT SHELF shelving system uses support posts formed with a plurality of elongated slots at regular vertical intervals for receiving the hanger brackets. The slotted support post can also have annular grooves as discussed above in the SUPER ERECTA SHELF shelving system. A notch in each hanger bracket receives a truncated corner of a shelf.
The hanger brackets used in the QWIKSLOT SHELF shelving system allow for easy adjustment of the shelves. A potential drawback in some applications, however, is that shelves secured by means of the hanger brackets do not provide the heavy-duty load bearing capacity of other shelving systems, such as the SUPER ERECTA SHELF shelving system.
Still another type of successful shelving system, sold and marketed under the trademark METROMAX and also assigned to the assignee of the subject invention, features a "knock-down" shelving system that uses triangular support posts. Such a system is the subject of U.S. Pat. No. 4,811,670, No. 4,964,350, No. 5,271,337, and No. 5,279,231.
In U.S. Pat. No. 4,811,670, a corner assembly for securing each corner of a shelf to the triangular support post includes a wedge member, a corner bracket structurally associated with the shelf and a collar. The wedge member snap-fits on the support post, and the collar and corner bracket form a sleeve around the support post. The formed sleeve fits against the support post and wedge member and supports the shelf by a wedging force.
The shelving systems in U.S. Pat. No. 4,964,350, No. 5,271,337, and No. 5,279,231, feature modular shelves in combination with the triangular support posts. The modular shelves include a rectangular shelf frame formed from two end beams connected to two side beams. A center beam may be inserted between the end beams, parallel to the side beams, to increase the load-bearing capacity of the system. A plurality of plastic shelf mats are adapted to be snap-fit onto the shelf frame. The shelf frame is secured to the support post by corner assemblies comprised of a corner portion of the end beam, a wedge member and a separate collar. A sleeve formed by the corner portion and the collar is seated on the support post and wedge member and secured by a wedging action. Two lock cylinders lock the collar to the corner portion to secure the sleeve.
While the design of the modular shelf provides many advantages, adjusting the shelf can, on occasion, require use of a hammer or other tool to disengage the formed sleeve from the wedge member for the same reasons discussed above in connection with the SUPER ERECTA SHELF shelving system.
Despite the significant utility and commercial success of the above-described shelving systems, a need exists for an improved support assembly in which the shelving system may be easily assembled and the shelves easily adjusted to different heights without the need for any tools, and in which the shelves are secured in a static manner to provide a load carrying capacity suitable for heavy-duty use.